Article on The Internet Mini Encyclopædia
HIF carburettor Petrol Fountain!
Restarting a rebuilt 1275GT using a HIF44 cobbled together from the original piston, dashpot, throttle cam, choke mechanism and dashpot cover and the remaining parts from a recycled HIF6 throttle body off a RSP Cooper...
On starting the pump we got a fuel fountain!!! (see left)
All adjustments were correct, the Facet Silver Top pump was regulated to 2.5 psi via a Purolator pressure regulator just 12" from the carburettor, the pump was located 12" from the tank and fed from a Purolator inline fuel filter.
We replaced the carb with a pressure gauge to check there WAS NOT excess fuel pressure, THERE WAS NOT.
The float/valve tab alignment was checked (below) and the clearance between the floatchamber body and the float was then progressivly increased from specification (see the Burlen Manual) to a point of being excessive ( in an attempt to increase the sealing pressure!)
We fitted a new float and THEN a new needle valve (both from Burlen Fuel Systems)
STILL a fountain of fuel pumped out!!!!! EVERY TIME
THREE WEEKS OF HEAD SCRATCHING........
During the swap over the blanking pipe for the breather (big bore pipe poking 45 degrees up out of the side of the carb) had been refitted on the fuel overflow (the narrower bore one)... this stopped the fuel feed working like a ballcock in a cistern as internal pressure was causing problems
THe cure was found when a spare HIF38 with neither tube blocked was tried out... NO FOUNTAIN
THEN finally no fuel pissing out even at 5psi when the blocked off overflow was UNBLOCKED
PASSING RECOMMENDATION Always change the complete needle valve (Get a VITON TIPPED one nt a DELRIN TIPPED one) and ensure the plastic filter head provided is also fitted.
Added by FB 09-09-2004 smelling strongly of old 4*! & Revised 19-09-2004 & 12-10-2004
What Carb/Carby/Carburettor do I have?
If you have the little silver aluminium tag under one of the dashpot screws, find the number and enter it here!
Thanks to Burlen Fuel Systems, the current owners of SU (added 20 02 03)
Carbs, alternatives to SU
There are several options, all tempered by considerations of cost and availability:
All these carbs are more sophisticated than the HIF44, and with the exception of the 28/36 should give a little top end power boost straight away. There are other options, but harder to get hold of and to get information on.
What models had which?
"According to the HBOL for the Metro, all 998 Metros from 1982 to 1989 were fited with HIF38 carbs.
All 1275s have HIF 44. These latter carbs have Red spring on 1275 but yellow on 1275 Turbo.
Hope this helps, but caution, it is from HBO Lies!"
Which Car is it from?
A friend of mine got an HS4 from a wrecker for his '77 1000. On the Id tag on the fuel bowl is the number AUD486. What's it from?
Answer 29 12 02 from jonas: "Its from a 1971-74 Austin Allegro 1275 Auto"
Carb icing, symptoms
1. Marginal condition: it feels like running out of fuel when you lift off; that funny whuuurrgggg sound as the engine dies. Restarts easily enough, but can refuse to idle. Thaws out in minutes if left, depending on air temp.
2. More serious version, usu. coming off 'cruise' the throttle
sticks and you go piling on.... like the return spring's gone. Lifting the pedal
with your foot does no good...
Carb to injection date
"When did carbs get the boot?"
October 1991 for Coopers, but other 1275 Minis had carbs up to 1993 model year
Carb Needles: Find out what needle you need or have... online
0.090" SU Needle Search Interface & 0.100" SU Needle Search Interface
and http://www.teglerizer.com/sucarbs/index.html an su carb links page!!!
Carb air vacuum leaks (20/12/02)
Finished the transplant of the rebuilt twin HS2's onto the 998 along with an LCB and single box zorst. I seem to be having trouble keeping the revs down. Got it started and the revs start to increase and don't seem to stop. Throttle is closed, and only a tiny bit of choke gets it started. Push the choke in and it stops. Pull it a bit more and it goes up and up.
Check the fast idle. It's the little screw that nudges the throttle open when you pull the choke. Try reducing it a little.
Oh and it started making a high pitched noise that goes just before it stalls. Get louder with throttle, seems to be coming from carb area. Never made it before!
Ah... you need to find where this is coming from. It sounds like a vacuum leak to me which could well be the cause of all your problems.
Tip from Ade after Adyspell 2000 checking ;)
Carb Jet Separated from Adustment Mechanism
"Dave came round over the weekend and provided a little sensibility to the engine that was well needed, and checked the wiring and set the dizzy to where it should approximately be.
With this set we started to turn the engine over.
Much not quite starting and clouds of smoke puffing out of the carb got us a little worried.
All appeared well, but we just couldn't fathom it. The only point we had to go on was the nonleveling of the carb jet. A point that appeared to be a minor problem.
I removed the carb, and stripped it down, starting at the float bowl on the underside. (Hif 38 carb)
As soon as i'd removed the base plate i could see the problem.
Somehow, the jet had become removed from the plate that raises/lowers it, depending on the mixture, and was sitting on the base of the bowl. Turning the mixture screw did nothing to the amount of fuel coming through, since the jet wasn't moving. It turned out that the mixture was about as rich as it could get.
So, i cleaned out everything, and refitted the jet properly, and refitted the carb. I connected the choke and the accelerator, and started the car. It caught first time, but died quite quickly, probably due to the fact that i flooded it soon after it started. I have to seal the exhaust again tomorrow, so i shall give it another go then. I think the compression of a sealed exhaust will go a long way to help sorting out the issues of the car not starting. Nearly there then!"
Info From Gareth, 28/12/02
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